fixed issue with eggs in percolation request for 1 shard

src/main/java/org/elasticsearch/percolator/PercolatorService.java

@@ -847,16 +847,11 @@ public class PercolatorService extends AbstractComponent {
             return null;
         }
 
-        InternalAggregations aggregations;
-        if (shardResults.size() == 1) {
-            aggregations = shardResults.get(0).aggregations();
-        } else {
         List<InternalAggregations> aggregationsList = new ArrayList<>(shardResults.size());
         for (PercolateShardResponse shardResult : shardResults) {
             aggregationsList.add(shardResult.aggregations());
         }
-            aggregations = InternalAggregations.reduce(aggregationsList, new ReduceContext(bigArrays, scriptService));
+        InternalAggregations aggregations = InternalAggregations.reduce(aggregationsList, new ReduceContext(bigArrays, scriptService));
-        }
         if (aggregations != null) {
             List<SiblingReducer> reducers = shardResults.get(0).reducers();
             if (reducers != null) {

src/test/java/org/elasticsearch/percolator/PercolatorFacetsAndAggregationsTests.java

@@ -20,12 +20,14 @@ package org.elasticsearch.percolator;
 
 import org.elasticsearch.action.percolate.PercolateRequestBuilder;
 import org.elasticsearch.action.percolate.PercolateResponse;
+import org.elasticsearch.common.settings.ImmutableSettings;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.AggregationBuilders;
 import org.elasticsearch.search.aggregations.Aggregations;
 import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms;
+import org.elasticsearch.search.aggregations.bucket.terms.Terms.Order;
 import org.elasticsearch.search.aggregations.reducers.ReducerBuilders;
 import org.elasticsearch.search.aggregations.reducers.bucketmetrics.InternalBucketMetricValue;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
@@ -70,20 +72,18 @@ public class PercolatorFacetsAndAggregationsTests extends ElasticsearchIntegrati
             expectedCount[i % numUniqueQueries]++;
             QueryBuilder queryBuilder = matchQuery("field1", value);
             client().prepareIndex("test", PercolatorService.TYPE_NAME, Integer.toString(i))
-                    .setSource(jsonBuilder().startObject().field("query", queryBuilder).field("field2", "b").endObject())
+                    .setSource(jsonBuilder().startObject().field("query", queryBuilder).field("field2", "b").endObject()).execute()
-                    .execute().actionGet();
+                    .actionGet();
         }
         client().admin().indices().prepareRefresh("test").execute().actionGet();
 
         for (int i = 0; i < numQueries; i++) {
             String value = values[i % numUniqueQueries];
-            PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate()
+            PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate().setIndices("test").setDocumentType("type")
-                    .setIndices("test").setDocumentType("type")
                     .setPercolateDoc(docBuilder().setDoc(jsonBuilder().startObject().field("field1", value).endObject()));
 
             SubAggCollectionMode aggCollectionMode = randomFrom(SubAggCollectionMode.values());
-            percolateRequestBuilder.addAggregation(AggregationBuilders.terms("a").field("field2")
+            percolateRequestBuilder.addAggregation(AggregationBuilders.terms("a").field("field2").collectMode(aggCollectionMode));
-                    .collectMode(aggCollectionMode ));
 
             if (randomBoolean()) {
                 percolateRequestBuilder.setPercolateQuery(matchAllQuery());
@@ -135,20 +135,18 @@ public class PercolatorFacetsAndAggregationsTests extends ElasticsearchIntegrati
             expectedCount[i % numUniqueQueries]++;
             QueryBuilder queryBuilder = matchQuery("field1", value);
             client().prepareIndex("test", PercolatorService.TYPE_NAME, Integer.toString(i))
-                    .setSource(jsonBuilder().startObject().field("query", queryBuilder).field("field2", "b").endObject())
+                    .setSource(jsonBuilder().startObject().field("query", queryBuilder).field("field2", "b").endObject()).execute()
-                    .execute().actionGet();
+                    .actionGet();
         }
         client().admin().indices().prepareRefresh("test").execute().actionGet();
 
         for (int i = 0; i < numQueries; i++) {
             String value = values[i % numUniqueQueries];
-            PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate()
+            PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate().setIndices("test").setDocumentType("type")
-                    .setIndices("test").setDocumentType("type")
                     .setPercolateDoc(docBuilder().setDoc(jsonBuilder().startObject().field("field1", value).endObject()));
 
             SubAggCollectionMode aggCollectionMode = randomFrom(SubAggCollectionMode.values());
-            percolateRequestBuilder.addAggregation(AggregationBuilders.terms("a").field("field2")
+            percolateRequestBuilder.addAggregation(AggregationBuilders.terms("a").field("field2").collectMode(aggCollectionMode));
-                    .collectMode(aggCollectionMode ));
 
             if (randomBoolean()) {
                 percolateRequestBuilder.setPercolateQuery(matchAllQuery());
@@ -194,12 +192,76 @@ public class PercolatorFacetsAndAggregationsTests extends ElasticsearchIntegrati
     public void testSignificantAggs() throws Exception {
         client().admin().indices().prepareCreate("test").execute().actionGet();
         ensureGreen();
-        PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate()
+        PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate().setIndices("test").setDocumentType("type")
-                .setIndices("test").setDocumentType("type")
                 .setPercolateDoc(docBuilder().setDoc(jsonBuilder().startObject().field("field1", "value").endObject()))
                 .addAggregation(AggregationBuilders.significantTerms("a").field("field2"));
         PercolateResponse response = percolateRequestBuilder.get();
         assertNoFailures(response);
     }
 
+    @Test
+    public void testSingleShardAggregations() throws Exception {
+        assertAcked(prepareCreate("test").setSettings(ImmutableSettings.builder().put(indexSettings()).put("SETTING_NUMBER_OF_SHARDS", 1))
+                .addMapping("type", "field1", "type=string", "field2", "type=string"));
+        ensureGreen();
+
+        int numQueries = scaledRandomIntBetween(250, 500);
+
+        logger.info("--> registering {} queries", numQueries);
+        for (int i = 0; i < numQueries; i++) {
+            String value = "value0";
+            QueryBuilder queryBuilder = matchQuery("field1", value);
+            client().prepareIndex("test", PercolatorService.TYPE_NAME, Integer.toString(i))
+                    .setSource(jsonBuilder().startObject().field("query", queryBuilder).field("field2", i % 3 == 0 ? "b" : "a").endObject())
+                    .execute()
+                    .actionGet();
+        }
+        client().admin().indices().prepareRefresh("test").execute().actionGet();
+
+        for (int i = 0; i < numQueries; i++) {
+            String value = "value0";
+            PercolateRequestBuilder percolateRequestBuilder = client().preparePercolate().setIndices("test").setDocumentType("type")
+                    .setPercolateDoc(docBuilder().setDoc(jsonBuilder().startObject().field("field1", value).endObject()));
+
+            SubAggCollectionMode aggCollectionMode = randomFrom(SubAggCollectionMode.values());
+            percolateRequestBuilder.addAggregation(AggregationBuilders.terms("terms").field("field2").collectMode(aggCollectionMode)
+                    .order(Order.term(true)).shardSize(2).size(1));
+
+            if (randomBoolean()) {
+                percolateRequestBuilder.setPercolateQuery(matchAllQuery());
+            }
+            if (randomBoolean()) {
+                percolateRequestBuilder.setScore(true);
+            } else {
+                percolateRequestBuilder.setSortByScore(true).setSize(numQueries);
+            }
+
+            boolean countOnly = randomBoolean();
+            if (countOnly) {
+                percolateRequestBuilder.setOnlyCount(countOnly);
+            }
+
+            percolateRequestBuilder.addAggregation(ReducerBuilders.maxBucket("max_terms").setBucketsPaths("terms>_count"));
+
+            PercolateResponse response = percolateRequestBuilder.execute().actionGet();
+            assertMatchCount(response, numQueries);
+            if (!countOnly) {
+                assertThat(response.getMatches(), arrayWithSize(numQueries));
+            }
+
+            Aggregations aggregations = response.getAggregations();
+            assertThat(aggregations.asList().size(), equalTo(2));
+            Terms terms = aggregations.get("terms");
+            assertThat(terms, notNullValue());
+            assertThat(terms.getName(), equalTo("terms"));
+            List<Terms.Bucket> buckets = new ArrayList<>(terms.getBuckets());
+            assertThat(buckets.size(), equalTo(1));
+            assertThat(buckets.get(0).getKeyAsString(), equalTo("a"));
+
+            InternalBucketMetricValue maxA = aggregations.get("max_terms");
+            assertThat(maxA, notNullValue());
+            assertThat(maxA.getName(), equalTo("max_terms"));
+            assertThat(maxA.keys(), equalTo(new String[] { "a" }));
+        }
+    }
 }